The present research aimed to find out the usability of non-topical terms used in indexing of Islamic sciences resources in information retrieval process. The research population carried out with analytical survey method, was the users of the Islamic Sciences Information Management Database designed by Institute of Islamic Information and Document Management. A sample of 50 researchers familiar with the Islamic Sciences Information Management Database were selected by purposive convenience sampling method. Data gathering tools used in this study were three questionnaires developed by the researchers. The first questionnaire evaluated the end users’ experience of the database, the second one was an open-ended questionnaire to get feedback from users about the retrieval process and the third one was a close-ended questionnaire related to the research hypotheses. The questionnaires validity was determined by information retrieval and storage specialists, and their reliability was confirmed by Cronbach’s alpha test. Inferential statistics was applied to test the research hypotheses. Research findings indicate that using non-topical terms for expanding search query in Islamic Sciences Information Management Database led to desirable results. However, developing non-topical terms based on suggestions from end users is necessary. Findings also showed that there was a proper equivalence relationship among non-topical terms. Findings of present research indicated that paying attention to non-topical terms and using equivalence relationship between them along with applying topical terms can lead to relevant and desired results in information search and retrieval.